Agree accidentally clobbering the clipboard is super annoying. Clipboard history apps are a godsend. Like Paste on Mac, or Windows has it built in.
I came here to exactly comment about this. I use Maccy and it is godsend. It is single most valuable productivity hack.
I first encountered clipboard history in Jetbrains Rubymine editor
The Mac now has a clipboard history as well, it's just a bit awkward. You can open Spotlight with ⌘Space, and within Spotlight open the clipboard manager with ⌘4.